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Reordered two functions.

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Added two metafunctions to create table columns and table indexes.


git-svn-id: https://samskivert.googlecode.com/svn/trunk@1440 6335cc39-0255-0410-8fd6-9bcaacd3b74c
This commit is contained in:
eric
2004-05-28 01:54:47 +00:00
parent d7645dd586
commit 1d62c33ee0
1 changed files with 75 additions and 18 deletions
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projects/samskivert/src/java/com/samskivert/jdbc/JDBCUtil.java
+75 -18
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@@ -1,9 +1,9 @@
//
// $Id: JDBCUtil.java,v 1.9 2004/05/27 02:04:34 eric Exp $
// $Id: JDBCUtil.java,v 1.10 2004/05/28 01:54:47 eric Exp $
//
// samskivert library - useful routines for java programs
// Copyright (C) 2001 Michael Bayne
//
//
// This library is free software; you can redistribute it and/or modify it
// under the terms of the GNU Lesser General Public License as published
// by the Free Software Foundation; either version 2.1 of the License, or
@@ -183,7 +183,28 @@ public class JDBCUtil
return matched;
}
/**
* Returns true if the table with the specified name exists and
* contains a column with the specified name, false if either
* condition does not hold true. <em>Note:</em> the names are case
* sensitive.
*/
public static boolean tableContainsColumn (
Connection conn, String table, String column)
throws SQLException
{
boolean matched = false;
ResultSet rs = conn.getMetaData().getColumns("", "", table, column);
while (rs.next()) {
String tname = rs.getString("TABLE_NAME");
String cname = rs.getString("COLUMN_NAME");
if (tname.equals(table) && cname.equals(column)) {
matched = true;
}
}
return matched;
}
/**
* Returns true if the index on the specified column exists for the
* specified table. false if it does not. <em>Note:</em> the names are
@@ -207,24 +228,60 @@ public class JDBCUtil
}
/**
* Returns true if the table with the specified name exists and
* contains a column with the specified name, false if either
* condition does not hold true. <em>Note:</em> the names are case
* sensitive.
* Adds a column (with name 'cname' and definition 'cdef') to the
* specified table.
*/
public static boolean tableContainsColumn (
Connection conn, String table, String column)
public static void addColumnToTable (Connection conn, String table,
String cname, String cdef)
throws SQLException
{
boolean matched = false;
ResultSet rs = conn.getMetaData().getColumns("", "", table, column);
while (rs.next()) {
String tname = rs.getString("TABLE_NAME");
String cname = rs.getString("COLUMN_NAME");
if (tname.equals(table) && cname.equals(column)) {
matched = true;
}
if (JDBCUtil.tableContainsColumn(conn, table, cname)) {
Log.info("Database table '" + table + "' already has column '" +
cname + "'.");
return;
}
return matched;
String update = "ALTER TABLE " + table + " ADD COLUMN " + cname + " " +
cdef;
PreparedStatement stmt = null;
try {
stmt = conn.prepareStatement(update);
stmt.executeUpdate();
} finally {
close(stmt);
}
Log.info("Database column '" + cname + "' added to table '" + table +
"'.");
}
/**
* Adds an index on the specified column (cname) to the specified
* table. The index is named after the column.
*/
public static void addIndexToTable (Connection conn, String table,
String cname)
throws SQLException
{
if (JDBCUtil.tableContainsIndex(conn, table, cname)) {
Log.info("Database table '" + table + "' already has an index on " +
"column '" + cname + "'.");
return;
}
String update = "CREATE INDEX " + cname + " on " + table + "(" + cname +
")";
PreparedStatement stmt = null;
try {
stmt = conn.prepareStatement(update);
stmt.executeUpdate();
} finally {
close(stmt);
}
Log.info("Database index '" + cname + "' added to table '" + table +
"'");
}
}